Kristen Stewart and Robert Pattinson have reportedly called it quits over the weekend.

The “Twilight” stars had been dating for more than three years, and separated briefly after Stewart’s dalliance with her “Snow White and the Huntsman” director Rupert Sanders last summer.

Their alleged split appears to be fueled by Stewart’s absence at Pattinson’s 27th birthday part on May 13.

“It was very strange that they didn’t celebrate Rob’s birthday together,” a source told People. “He had friends over at his house, but Kristen was not part of the celebration. For the past few days, they have not spent any time together.”

The magazine also reported that the two have been spending more time apart in their own homes since the “Cosmopolis” actor returned from New York to LA earlier this month.

However, the source noted that there’s a chance the two could get back together.